Gun sight



July 20, 1948. s. H; cRossMAN GUN SIGHT 2 Sheets-Sheet l Filed June 26, 1944 5TEPHENH ERUS5MAN) Sum/m94,

MMM

July 20, 1948. s. H. cRossMAN 2,445,314

v GUN SIGHT Filed June 26, 1944 2 Sheets-Sheet 2 STEPHEN H ERDSEMAN,

Patented July 20, 1948 attriti-i wenn UNITED sTATEs PATENT oFFlcE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Governmentfor governmental purposes without the paymentto me of any royalty thereon.

The invention relates to sights suitable for use on ordnance or for other purposes and has for an object to oiler a novel, small, simple, a'nd inexpensive mount having important functional advantages.

It is a special further aim to present a construction particularly adapted to the use of an optical device capable of producing collimated rays fof light representing the image of the target, orV a telescopic image.

The invention in its present embodiment is designed so as to be applicable to use on firearms, and small caliber ordnance, but has capabilities of adaptation to more extensive use including heavy ordnance, if necessary, or desirable. As shown, it is designed for appli-cation particularly to small arms such as a rifle, mortar. or rocket launcher, and in the specific form Apresented is for.l use on the rie when employed for launching grenades or the like, or on a rocket launcher or mortar for direct fire, where much higher trajectories are involved for usual ranges than are involved in the use of the ball cartridge at the same ranges.

It' is an important; aim of the invention to presentl a sight mount which may be produced a1- most entirely from sheet metal stampingsyet with dependablev sight functions, and free from objectionable liability of derangement incident to'ordlnary. army service use.

It is a special ypurpose to give a sight which will bev extremely simple in function as to adjustment; or setting, for specific ranges, so that enlisted personnel will have no difficulty inobtaining' accurate and proper settings for the usual ranges involved in the use ofa sight on weapons of the oliaracter'indicated'.

It is a salient attainmentv of the-invention that itv may be quickly changed as t'o'calibra'tion, tol coordinate its function with various kinds of ammunition having differing trajectory characterlstics. That is to say, projectiles usually fired may be of different weights, and different propellant components, according to the requirements of combat which have been provided for and one would ordinarily have a higher trajectory than 2 another, so that an angular setting of the sight for one would not give the same range with other ammunition.

It has also been proposed to use for shells of the same bursting characteristics, a series of dif'- ferent propellant charges appropriate to short, medium, or long range firing, and each having its special trajectory forms.

It has therefore been an aim of the invention to enable the provision of range scales on the sight appropriate to the several forms and in such manner that they may be selected alternatively and used effectively by the soldier, either as interchangeable scale plates or as alternative scales on a single dial plate, one to be selected and used according to the particular ammunition in use at the moment. This feature also enables the use of the same manufacture on rifles for grenade launching, adapted to the single service propellant cartridge M3, and to the same with the vitamin pill auxiliary cartridge of propellant, set in or at the tail of the grenade shell; and to use on the popularly named bazooka or rocket launcher, as well as other weapons, which may include the development of Stokes type mortars, either in their conventional use or in the expected development thereof to from-the-shoulder ilring, and other low or high elevation use of the mortar. The same feature also will enable the ready application of the device to use on larger caliber ordnance should it appear desirable, by the provision of the special scale plate required for the particular gun and a specific ammunition therefor.

It is a highly important aim of the invention to obviate the need for separate front and rear sights on weapons such asy mortars, rocket launchers and the like Where unusually high trajectories in relation to range are involved. In such cases Ithe front sight would have to be extremely bulky for a given scale of ranges, and it would not be practicable to include a satisfactory full scale of ranges without objectionable interference with handling and shipment of the wea-pon equipped with effective front and rear sights. My invention, on the contrary, enables the use of a single small device, which may be mounted in the position of the rear sight only, and will enable more accurate laying of the weapon.

Additional objects, advantages and features of invention reside in the construction arrangement and combination of parts involved in the embodiment of the invention, as will be apparent or understood from the following description and accompanying drawings, wherein Figure 1 is a fragmentary side elevation of a rocket launcher on which my invention is incorf porated;

Figure 2 is a rear view of the sight;

Figure 3 is a horizontal section on the sight axis of Fig. 2;

Figure 4 is a section on the line 4-4 of Fig. 2;

Figure 5 is a detail top view ofthe receiver; Figu-re 6 is a lplan of the pivot base of the range arm;

Figure 7 is a section on the line 1-1 of Fig. 6; Figure 8 is a plan of a modied base plate, and interchangeable dial;

Figure 91s a section on the une s-s of Fig. s;

Figure 10 is a plan of the blank for the eyepiece mounting.

Referring more particularly to the drawings, there is shown a portion I5 of a tube or barrel. which may be that of a rocket launcher, although with appropriate elevation scales on my invention the barrel might be that of a rie or the tube of amortar. A

My sight device is applied permanently to the launcher barrel .or tube, although, as Vwill appear, a base element only may be permanently attached to the left side of a barrel while the remaining sight parts are applied when required, making it particularly valuable for use on rifles, where occasional use of a` grenade launcher on theriiie is lntermitted by extensive use of the arm with ball ammunition. The sight includes a vertical base plate I6 and lower bracket arm I1, formed integrally, the base plate being a planiform part with a generally sector-shaped central area I8, but being extended below and above to parallel boundaries I9 and 20 respectively. From the lower boundary, the bracket part II is extended and bent sharply on the boundary I3 through an langle of approximately 125 degrees, so as to extend upward to the right at an angle to enable its ready attachment to a barrel or tube. The extension 2I of the upper part of the plate may be left in the plane of the sector portion where the device is to be attached to a large tube such as that of a rocket launcher and for rifles may be bent to the right so that the planiform body of the plate may lie fiush with the face of the stock, which would be opened to allow placement of the device. In the present instance the extremity of the arm II is attached as by spot welds, to the under surface of the tube I5, while the extreme upper edge of the planiform vertical plate is laid on a tangent to, and spotwelded to, the left side lof the tube.

The plate I6 is formed with an aperture 22 at the' center of the sector area and an arcuate concentric sector edge 23 extends to the right beyond the extension 2I and bracket arm I.'I. A smaller concentric approximately semi-circular base ear 24 'is formed on the left side of the plate I6. On the upper part of the sector area I8 near the edge 23 a scale 25 of elevations measured in hundreds of'yards is marked on the base plate in a concentric series of numbers denoting respective ranges. The values are proportionate to the order of the units marked, beginning at the bottom of the scale.

An elevation or-range arm 26 is provided, consisting of a resilient, planiform, sheet metalplate,

of the same radial dimension as the 569W! @ma I3, and with a centrally apertured pivot base 21 alined with the aperture 22 and ear 24, but of much less extent angularly than the sector area I8. It is secured pivotally to the base plate by a rivet or screws 28 and I0 engaged in the axial apertures of both. The range arm has a radial upper edge portion 29 extending through the'arc ion which the scale 25 is formed, and an outturned ear or stop 30 is struck from the material of the plate I6 to engage an upper edge part of the elevation arm 26 when at the upper limit of its movement .with respect to the scale 25. A similar lower stop 3l is struck from the plate I6 'to engage the lower edge of the arm 426 when the top edge 29 of the latter is at zero elevation of 'the scale 25. The angular dimension of the elevation arm 26 may be varied, but is at least sul- ,cient to cover- A the entire scale 25 except the last Lmark thereon when the arm is at the upper limit of its movement.

Below the scale, and within the sector area, a series of indentations 32 are formed in the plate I6 concentric With the aperture 22 .spaced angularly at the same intervals as the units marked on the scale 25; and on the underside of the arm 26, a tooth 33 is formed by pressing, shaped to fit snugly in the indentations 32 alternatively.

The indentations may be located on a line adjacent the edge 23 below the'scale 25, or may be located elsewhere on the plate I6 and the tooth 33 correspondingly positioned. The tooth 33 is so located on the arm 26 that when engaged in one of the indentations 32, the top radial edge 23 of the arm 26 will be alined with one ofI the divisions of the scale 25, exposing immediately over the arm 26 the number denoting'the range value of the particular setting of the arm 26. l

On its lower edge, the arm 26 hasy an out turned flange or finger piece 34 adapted to be grasped between the thumb and forenger, or pushed by any of the fingers or other members to move the arm upward or downward, when it is desired to change the setting of the sight, as will be explained hereinafter. The pivot base 21 of the elevation arm 26 has a number of nodules 35 `formed on its under side distant from the pivot and opposite the major body portion of the arm and tooth 33, and bearing frictionally on the ear 24 so that the tooth is pressed rmly toward the plate I6, assuring rm engagement of the tooth in the indentations 32. The latter are preferably V-shaped in section, on the arc of the series, and radially elongated; and the tooth may approximatera knife edge, so that when it is brought over either sloping side of one indentation, it will tend to slip to a central position in the indentation.

l While the indentations have been shown in the same number and spacing as the ordinals of the scale, the indentations may be multiplied, if desired, so as to position the edge 29 to indicate fractional parts of the main divisions of the scale, as Well as the latter, in addition. To accommodate any additional fractional divisions, additional indentations may be in a parallel series and staggered in relation to the first ones.

In the' present instance, the indentation 32 corresponding to'the zero position of the arm 26 on the scale 25, is on a radius of the pivot parallel to the axis of the tube I5, and the tooth 33 is on the medial radius 'of the arm 26, so that the latter extends also parallel to the tube axis when at zero position. These relations of scale, indentation, `and tooth t0 the tube or barrel of the weapon iliiiiliri Ril@ 5` are vnot arbitrary or essential as will appear, but' are convenient in the present instance for a` presentation of theinvention.

Fixed on the pivot base 21 of the'arm 2B, there is a channelled foot piece or receiver 36, formed of llat sheetmetal, having outturned guides 31 thereon, parallel to the radius on which the tooth 33 `is Ilocated, and including in'turned lips or overhang's 36, parallel to the iiat body portion of the piece and forming opposed deep grooves 3 6 thereunder. Midway of each guide an indentation 40 is formed in the extreme outer part of the guide extending into the groove slightly. ',Ihe guides are equally spaced on opposite sides of the pivot of the arm 26, and the flat body portion ofthe receiver is apertured at 4| so vas' to clear the pivot rivet or screw 28, the lips 38 being likewise partly cut away at their middle partsin alinement with the aperture 4|-.

An eye-piece frame or carrier 42 is provided, stainped ffrom sheet spring steel including a bivfnrliated shank 43 having spaced spring legs .4 4 provided iwith outturned iiat feet 4 6'- arranged in a-commonplane to which the shank is normal, .and adapted, when moderately compressed, to slide respectively and simultaneously under the lips-fof the receiver 36. The eye-piece 42 comvp ris'zsja mounting for a lens 54 or the like whichv may Ibe a polarizerof light formed in one piece lfom'ilat sheet stock, substantially of the form shown in Fig; 2.

The blank for the eye-piece mounting consists of a substantial rectilinear narrow strip of substantially uniformwidth throughout except forI broadened portions 46' at respective ends thereof, 1

and-tworing side portions 46 near its middle. each having lateral yil'ange extensions 41 at opposite sides. A narrow longitudinal flexible part v48 connects these wider parts at the 'middle of the piece. rigid ring sides ,46, each inthe form of a segment or a circle conforming to the size of a lens or the liketobe enclosed, theflange portions 41 being turned inward in parallel relation as retainers for an inserted lens 54 or other circular member. lThe iiexible connection '46 is also shaped to the This blank .is shaped to produce lateral to enter the notches 53, when .the feet will spring' apart against the guides, engaging on each sidev of the indentations.

be readily formed, adapted to be opened at'the J- meeting of the parts 49 for emplacement vor removal of a lens or other circular member 5,4 within thevring, to be embraced and retained by the ring and flanges 41 when the ring is closed. End

portions of the blank outwardly of the meeting parts 49 are bent outwardly-and radially so that they may be brought into close mutual parallel abutment to form the shank 43. One of the shank parts is drilled and tapped midlenjgth and the other drilled to aii'ord la larger aperture 'ias to form parallel legv parts 44 when the shank parts are secured by the "screw 5|. Intermediately of the length of each of the broadened end .portions 45, the outermost material of .the blank is bent at right angles on a line at right angles tothe direction of the adjacent leg, to form the foot 46. The outermost edges 5 2 of the feet are `formed with notches. 53 midway thereofV of a tion.

A lens device or other refractor 6 4' is provided, of circular form and of a diameter to be received snugly -tvithinthe ring 6|! and its flanges 41 when the shank parts 43 are brought together and secured.' VIt should be understood that the axis of the ring 50, at ,zero position of the arm 24.' is parallel to the axis of the tube I6.

- This`lens device may be a collimator lens, or system, adapted to project rearwardly eollimated rays defining the image of a target brought into fthe line of sight of the instrument. The device .carried by the ring .60 may alternatively be small telescope projecting forwardly or at both sides of the'ring. In one construction the in-I serted part has 'consisted of an axial light-polarizer crystal, 4or constructed polarizing material,

having refracting rings concentric with the axis ofthe ring 562 Except so say that such collimating or polarizing o'r refracting material is avail' able commercially from the Polaroid Co. of Cambridge. Massachusetts, the details thereof will not be describedsince none of the alternative devices comprise original features of the present inven- In Figures 8 and 9, there is illustrated a modification of the invention in which the body 64,' corresponding to the base I6 before described, is substantially of the same size and contour, but the upper stop 30 is omitted, anden the edgeY 23', corresponding tothe arcuate edge 23 before described, a broad ear 6| is integrally formed in a plane with the remainder of the plate, a rectilinear, narrow slot 62 being formed there-' through, without, and tangent to, a geometrical projection of the arc defining the sector .area IVI' which corresponds to the area I6. There is 'no scale formed o n this body 60, nor any indentaf tions such as were on the plate i6. aperture 22' corresponding to the one 22 is provided inthe base ear 2 4'. This body is mounted permanently as before on the tube or barrel of the weapon on which it is to serve and the other sight ele'- ments applied as required.

There i's provided a dial or scale plate 63 with pivot base 66 of a size and shape to include there-b under the base ear 24' and sector area'l' and to extend below the ear 3|' (which is in substan' tially the same relative location with respect to the aperture 22 fand the horizontal as the ear 3|),t The plate 63 hasfo'rmed therein a slot 64 near. its lower edge to receive 4the ear 3| loosely therethrough, the latterprojec'ting beyond the plate 63 when the latter is so applied. The plate 6 3 is formed with an arcuate edge portion 65.coi`n1 dent with the edge 23'; and is of a vertical extent to include the area corresponding. to that occa- 4 piedby the scale' 25 of the plate i6.

On the edge 65 there is formed a broad 4r: aic l ifw.l tongue 66, having rectilinearv upper and lower. edges parallel to the mean radius of the tongue and with lrounded 'or otherwise inclined corners 61. This' tongue is positioned to' aline with the slot 6 2 and is bent at an angle of nearly 90 degrees to the plate 63, so as to enter the 'slot 62 when the plate .63 is laid over the area I8' of the body 60. The extremity of the tongue 66 is bent outward to extend parallel to, and close to, the back side of the base plate 60, preventing withdrawal of the tongue from the slot except when the pivot end 68 of the dial plate is lifted away from the base 60. A pivot aperture 69 is formed in the end 68 to aline with the aperture 22"and to receive pivot screws 16, substantially as in Fig. 3.

The width of the tongue 66'is such as to t snugly at its edges against the ends ofthe slot BI-an important function, determining the proper calibration position of the dial plate with respect to the weapon. The plate .63 is provided in its upper part with a. scale 25 the same as the one 25 before described and in the same arc concentric with the apertures 22 and 69, and below the scale a concentric series of indentations 32' similar to those 32 and in the same relation to the scaleas before indicated. Y

With the device of Figs. 8 and 9, the saine range arm 26 before described is used Without change in the particular embodiment shown, the' arm being laid over the dial plate 63 after the latter is positioned, and the pivot screws 10 engaged through the arm 26, plate 63 and plate 60, the

head of the screw engaging the outer face of' the arm to compress the latter and dial plate to proper operative position on the plate 66.

v only be necessary to pull the base of the armvi 26 from place by axial translative movement and tongue 66 drawn from the slot 62, and the plate 63laid aside. Another dial plate of identical size, contour and structural features is substituted, differing in the specific calibration of its scale, which will be appropriate to the ammunition next to be used. After placing of the new dial plate, the arm26 is returned to position thereover, and the screws 'l0 and 28 replaced, holding the new assembly in place, after which the eye-piece is returned to its place by sliding its feet into the receiver, until the notches 53 snap onto the indentation 40.

The aiming of the weapon with the new ammunition may then be proceeded with, as before described.v l

By substituting forl the screw 10 a permanent stud set in the plate 60, and forming it with one element of a snap fastener the other element of which is incorporated in the base 21 of the elevating arm'26, the removal and replacement of the parts may be greatly expedited. It would then While the device is designed for use on a weapon fired from the shoulder, it may be used in other situations as well.

In use, `the device being assembled in either1 al laying,`the arm 26 is shifted upwardly until its l upper edge 29 aiines with the iigure on the scale denoting the particular range linvolved. This moves the ring 50 around the axis of the pivot Z6- 16, the axis of the sightbeing tilted downward and causing the tube to assume the proper elevation when raised sufficiently at the muzzle to permit the marksman to view the target through the sight device 54 in the ring 50. With a good collimation of the rays defining .the target as viewed through the element 54, the percentage of angular error for the ranges in which rocket launchers, grenade launchers and mortar devices are used, is small, and very quick laying of the weapon may be effected. 1

It is an advantage of a polarization or collimination device that accommodation of the eye of the marksman to the sight longitudinally of the Weapon is automaticallyA accomplished without adjustment of the eye-piece, since the eye of the user is spaced rearwardly of the sight at all times, it being unnecessary to apply the eye brow directly to the ring 5U orany other rproject. ing mechanical part.

It is possible to provide a series of range scalesv similar to the one 25 on different arcs on the plate I6, or on the dial plate 63, each. one calibrated for a different ammunition; but to avoid the extreme likelihood of error in selection .of the proper scale, it is believed preferable'to use the construction of Figs. 8 to 10. In such case, when a change of ammunition is decided upon the legs of the eye-piece frame are compressed and the feet drawn from the receiver 30 and the eye- 68 of the dial plate 63 may then be lifted, the' sure in the opposite direction.

While the invention has' been' disclosed with great particularity in the best embodiment known` to me, it will nevertheless be understood that vari` ous changesin the construction, arrangement and'.

combination of parts, substitution of materials l and substitution of equivalents -mechanically -orotherwise other than those speciiically'claimed may be made without departing lfrom the spirit of the invention as moreparticularly set forth in the appended claimswherein I claim:

.1. A gun sight comprising. a base including a plate, a sight piece pivoted thereon on.an axis normal thereto, a-scale on the plate concentric with said axis, a pointer device movable with the sight piece, and a sight having any axis normal to the pivot axis mounted on said sight piece, said sight yconstructed to project an image of a. target in line with said axis of the sight, said base plate lcomprising a planiform sheetlmetal .blank having a lower portion bent upward at the rear to form a bracket arm for attachment to the underside of a tube or the like, the upper edge portion of the plate being. extended for attachment at a tangent to the outer side of a tube .or the like. Y

3. The structure of .claim 2 in which the sight .piece holder comprises a narrow blank of resilient sheetmetal having broadened extremities and at least one intermediate broadened part, the intermediate part of thestrip being bent into a circulariorm constituting said4 ring, opposite edges in said intermediate broadened part bent inward to embrace the .edge portion of an insertedi lens or the like, the end portions ofthe strip' being bent outward sharply in abutment at their junction with the circular part and connected to formsaid shank, the extremities being spaced apart, constituting .said iurcation.y

" 4.y A sight comprising a' base member a planiform plate, van arm pivoted thereon for sweeplmove'ment Aagainst the. face of the plate..

meansto indicate the angular positions of the Ahaving I that arm on the plate, a receiver on the arm at the pivot axis of the arm, a sight mount having a shank portion removably engageable With the receiver, and constructed to extend on the pivot axis of the arm, and a ring i'lxed on its extremity in a plane coincident with said axis.

5. The structure of claim 4 in which said rev ceived is formed with a diametrical channel across the pivot axis, medial projections at the sides of the channel, said shank having spring loaded spaced compressible foot portions formed with opposite parallel sides recessed to receive said projection when the shank is in operative position on the receiver.

6. The structure of claim 4 in which said arm comprises a resilient plate, a series of spaced indentations concentric with the pivot formed in the base plate each being V-shaped in cross section and a knife edge member on said arm alined with said series and adapted to engagethe indentations alternatively, said arm being stressed to press the tooth toward the base plate, whereby when the tooth engages the slopingside of an indentation it will tend to move to the middle of the indentation.

7. A sight comprising a body plate constructed for rigid attachment to the side of a Weapon and having a pivot part and a distant slot transverse to a medial radius from the pivot part, a dial plate having a pivot part concentric with that of the body plate and having a radial tongue of a. width to t snugly in said slot when the dial plate is flat on the body plate, a pivot means extending through said pivot parts, a scale on the dial plate concentric with its pivot part, an arm pivoted on said pivot means and movable over the first two plates, and means to yieldingly hold the arm at stages of movement adjacent said scale.

8. The structure of claim '1 in which the pivot means of said arm consists of a plurality of axially aligned detachable parts, said parts being coengaged with the said pivot parts of the body plate and dial plate.

9. A mount comprising a receiver support having opposed overhanging parts and including opposed inward projections, and a mount device having spaced spring legs having respective outturned parts to engage under respective overhangs and notched to receive said projections.

10. A sight comprising a base plate having a pivot member thereon, a dial plate adapted to be laid on the base and having a pivot part alined with the pivot member of the base, one of said plates having an opening distant from the pivot and the other having a projection to enter said opening, and a range arm pivoted on the dial plate at said pivot member.

11. The structure of claim 10 in Which said projection has an outturned extremity arranged to engage the base to hold the outer part of the dial vplate against separation until its pivot part is lifted from the base.

12. The structure of claim l0 in which said base and said dial plate are thin plates, said opening being an elongated slot extending at a substantial angle to an intersecting radius of the pivot part, and said projection is a tongue integral with its plate bent at an angle to extend through said slot, its extremity being bent outwardly to engage against the far side of the plate through which it is inserted, said tongue being of a width to engage snugly between the ends of the slot.

STEPHEN H. CROSSMAN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 168,404 Martinez Oct. 5, 1875 906,751 Swasey Dec. 15, 1908 1,190,121 Critchett July 4, 1916 1,940,875 Neuwirth Dec. 26, 1933 FOREIGN PATENTS Number Country Date '739,206 France Oct. 24, 1932 

